u-boot/drivers/mmc/pic32_sdhci.c
Stefan Herbrechtsmeier 6d0e34bf4e mmc: sdhci: Distinguish between base clock and maximum peripheral frequency
The sdhci controller assumes that the base clock frequency is fully supported by
the peripheral and doesn't support hardware limitations. The Linux kernel
distinguishes between base clock (max_clk) of the host controller and maximum
frequency (f_max) of the card interface. Use the same differentiation and allow
the platform to constrain the peripheral interface.

Signed-off-by: Stefan Herbrechtsmeier <stefan.herbrechtsmeier@weidmueller.com>
2017-01-23 15:37:42 +09:00

80 lines
1.7 KiB
C

/*
* Support of SDHCI for Microchip PIC32 SoC.
*
* Copyright (C) 2015 Microchip Technology Inc.
* Andrei Pistirica <andrei.pistirica@microchip.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <dm.h>
#include <common.h>
#include <sdhci.h>
#include <linux/errno.h>
#include <mach/pic32.h>
DECLARE_GLOBAL_DATA_PTR;
static int pic32_sdhci_get_cd(struct sdhci_host *host)
{
/* PIC32 SDHCI CD errata:
* - set CD_TEST and clear CD_TEST_INS bit
*/
sdhci_writeb(host, SDHCI_CTRL_CD_TEST, SDHCI_HOST_CONTROL);
return 0;
}
static const struct sdhci_ops pic32_sdhci_ops = {
.get_cd = pic32_sdhci_get_cd,
};
static int pic32_sdhci_probe(struct udevice *dev)
{
struct sdhci_host *host = dev_get_priv(dev);
const void *fdt = gd->fdt_blob;
u32 f_min_max[2];
fdt_addr_t addr;
fdt_size_t size;
int ret;
addr = fdtdec_get_addr_size(fdt, dev->of_offset, "reg", &size);
if (addr == FDT_ADDR_T_NONE)
return -EINVAL;
host->ioaddr = ioremap(addr, size);
host->name = dev->name;
host->quirks = SDHCI_QUIRK_NO_HISPD_BIT;
host->bus_width = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
"bus-width", 4);
host->ops = &pic32_sdhci_ops;
ret = fdtdec_get_int_array(gd->fdt_blob, dev->of_offset,
"clock-freq-min-max", f_min_max, 2);
if (ret) {
printf("sdhci: clock-freq-min-max not found\n");
return ret;
}
host->max_clk = f_min_max[1];
ret = add_sdhci(host, 0, f_min_max[0]);
if (ret)
return ret;
host->mmc->dev = dev;
return 0;
}
static const struct udevice_id pic32_sdhci_ids[] = {
{ .compatible = "microchip,pic32mzda-sdhci" },
{ }
};
U_BOOT_DRIVER(pic32_sdhci_drv) = {
.name = "pic32_sdhci",
.id = UCLASS_MMC,
.of_match = pic32_sdhci_ids,
.probe = pic32_sdhci_probe,
.priv_auto_alloc_size = sizeof(struct sdhci_host),
};